The present invention relates to ratchet drives, in particular for fluid operated wrenches and the like.
Continuous ratchet drives are known in the art. One of the known drives includes a ratchet gear and a pivoting lever arm which turns the ratchet gear during the advance stroke of a cylinder-piston unit, and also during the return stroke of the same. It has been found that since the tip of a pawl connected with the lever arm and engaging with the ratchet tooth moves relative to the ratchet tooth during a power stroke, a considerable friction is created and the ratchet teeth deteriorate with consistent use.
One of the solutions to eliminate this movement is proposed in the U.S. Pat. No. 4,644,829. However, this tool has a very complicated construction and is expensive to manufacture since it requires many parts.